摘要
Abstract
Concrete filled steel tube(CFST)arch bridges generally feature arch ribs as purely compression-bearing components.With the long spans and low width-to-span ratios,these bridges exhibit relatively low structural stiff-ness,making stability a critical concern for bridge designers.In light of this,the Shibatan Bridge on the Beijing-Yuxian Expressway are taken as an example to investigate the stability,mechanical characteristics at various load-ing stages,and failure modes of a CFST deck-type arch bridge;The finite element modeling and stable and nonlin-ear stability analyses,obtaining buckling modes and buckling eigenvalues(hereinafter referred to as buckling stability coefficients)of the bridge structure during construction and operation.Under nonlinear conditions,the buckling stability coefficient for the second-type stability problem was found to be 5％～10％lower than that of the first-type stability problem,indicating that nonlinear analysis can better reveal potential instability modes under complex loading conditions;Through parametric analyses of pier layout and construction sequences of various components,it was concluded that increasing the number of pier cap beams and optimizing construction procedures can enhance the stability of CFST deck-type arch bridges.These analytical results can provide valuable references for future engi-neering practices.关键词
上承式拱桥/钢管混凝土拱/非线性分析/稳定性分析Key words
deck-supported arch bridge/concrete filled steel tube arch/nonlinear analysis/stability analysis分类
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